Imagine living in a small, rural village. You are a subsistence farmer, growing vegetables, and have a couple of nice fruit trees. You also have a handful of livestock. In the middle of the village is a large piece of open land with juicy grass growing on it. Nobody is allowed to build there, because the leader of the village has decreed that this is common land. The intention is that everyone in the village graze their livestock on their own land, but because the properties are small, livestock can also graze on the common land to get enough food to be healthy.

One of your neighbours recently inherited his family's estate. He decides to graze his livestock on the common field exclusively, while he cuts the grass on his property to sell to others. Some of the other people in the village start to grumble about this, and a few even start doing the same. As more and more people start grazing their livestock only on the commons, more and more people start doing the same. Before too long, the field is over grazed, the ground compacted by all the trampling of heavy hooves, and left unusable for grazing.

This hypothetical scenario is called the Tragedy of the Commons. It is meant to illustrate how a resource, which is replenishable, can be completely depleted if everyone only looks out for their own self-interest. And the same thing is happening in Cape Town at the moment.

Cape Town is currently experiencing a drought. For various reasons that I am not going to go into, it may very well become the first large, modern, industrialised city to run out of water. When this happens, running water will be cut to residents and the government will ration water to citizen from certain water collection points.

The local government has been warning about the dire situation for more than a year. Even after poor rains the last rainy season, it took months for the reality to set in for many, if not most, of the citizens. At the time of writing, this "Day Zero" (where running water to household taps will be turned off) is three months—less than 100 days—away. With the realisation of what is now all but inevitable, one could a couple of weeks ago start seeing signs of panic. Many people who have lived comfortably all their lives now need to consider the unthinkable: not having easy, on-demand access to water.

It is almost needless to say what happened next. People started rushing to stores to buy bottled water. Buckets, basins and other containers sold out almost overnight. There are stories and rumours going around of people hoarding (municipal) water in large, 2200l tanks. Some stores were caught selling bottled water which was nothing more than filtered municipal water. These stories are unverified, but I find it plausible that people who have for months flaunted warnings would persist with selfish practices.

The municipal water supply is our commons. The Tragedy of the Commons is no longer a thought experiment for the citizens of Cape Town, but a reality. And as the Tragedy descends on the people, I believe that we can expect to see more base human behaviour to surface. This is what survivors of the Holocaust described as the people in the ghetto over time grew hungrier, more desperate, more scared1.

In saying this, I am not a doom prophet or cynic who thinks the worst of people. This is a real possibility; so much so that the authorities have announced that, should Day Zero hit, the military will be deployed to keep order. Desperation will not only be fuelled by the inconvenience of having to fetch water, but the lack of clean, readily accessible water can also see the outbreak of diseases, further spreading panic. And while Cape Town's rainy season is predicted to lie just beyond Day Zero, there is no guarantee that the catchment areas will receive plentiful rain. In other words, the dread of Day Zero may very well be a reality for a year or more.

Christians should not be surprised by the behaviour evoked by the Tragedy of the Commons at all. The Bible teaches that the default human nature is sinful and selfish. The comforts, conveniences and luxuries which a large, modern city such as Cape Town affords can hide that well (although poorer areas around Cape Town are already quite violent). Strip away the comforts, conveniences and luxuries, and the ugliness will soon become apparent.

Although not actually related to the Tragedy of the Commons, another thought experiment, the Prisoner's Dilemma, indicates that in a situation such as this, where a limited resource is desired, the "sensible" thing to do is to opt for the selfish option over the altruistic option of not being selfish and (naively) desiring that everyone will benefit the most if everyone acts fairly.

Here the Christian is again called to live apart from the rest of the world. Regardless of what makes sense, regardless of what unfairness we may witness, we are called to act justly and fairly, and to share the little which we may have. We are not to despair over how we see other people behave. Instead, we show that, when things get really tough, our faith remains unshaken and our character remains in tact; through the grace and mercy of our Lord, Jesus.

• 1. See Smith, Lyn. Forgotten Voices of the Holocaust In Forgotten Voices. London: Random House, 2005.